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 Thermal Expansion Tanks, UPC CODE 608.3
Author: kormanicus (CA)


I really need to get some input from the licensed plumbers on this forum. I currently work for a Home Warranty Company and my job is to approve plumbing work orders. One thing that I've noticed is most of the water heaters we replace in homes the technicians are not installing Thermal Expansion Tanks. From what I've researched, If a check valve or back flow prevention device is connected to the cold water inlet line this would create what is classified as a "closed plumbing system". So to account for the Thermal Expansion I've read that a Thermal Expansion tank must be installed. The only time Thermal Expansion tank isn't required is if there's an "open water system" where the pluming line is receiving a fresh flow of oxygenated water.

When I read the Water heater installation manuals, (Rheem, Bradford White, A.O Smith, State, GE, Bosch etc.) "all of them" have verbiage that emphasizes that if a check valve is installed or a back flow prevention device, then it's "a closed system" and a Thermal Expansion tank must be installed or the Water Heater Warranty will be voided.

When I dug a little deeper to see who is the governing body who mandates these codes I've found the (UPC-UNIFORM PLUMBING CODE)" is adopted by many municipalities. I've also saw that some adopt "International building Code(IRC).

When it comes to the UPC CODE 608.3 it states the following "Any water system provided with a check valve, backflow preventer, or any other normally closed device that prevents dissipation of building pressure back into the water main shall be provided with an approved, listed and adequately sized expansion tank or other approved device having a similar function to control thermal expansion. Such expansion tank or other approved device shall be sized and installed in accordance with the manufacturers recommendations."

Here's similar verbiage from the International Residential Building Code

"IRC 2009 P2903.4 Thermal expansion control. A means for controlling increased pressure caused by thermal expansion shall be installed where required in accordance with Sections P2903.4.1 and P2903.4.2. P2903.4.1 Pressure-reducing valve. For water service system sizes up to and including 2 inches (51 mm), a device for controlling pressure shall be installed where, because of thermal expansion, the pressure on the downstream side of a pressure-reducing valve exceeds the pressure-reducing valve setting. P2903.4.2 Backflow prevention device or check valve. Where a backflow prevention device, check valve or other device is installed on a water supply system using storage water heating equipment such that thermal expansion causes an increase in pressure, a device for controlling pressure shall be installed."

Now to my actual question. Since now as an employee of this Company, I'm aware that these codes exist, and from what I researched most residential homes have what is classified as "closed water systems" wouldn't it be my duty to ask the plumber if a homeowner has a "closed plumbing system" and if he responds "yes" wouldn't he be obligated by plumbing code to install an Expansion Tank, and would we as a Company be liable if we're approving Water Heater replacements in "closed plumbing systems" with nothing to account for thermal expansion? From what I've researched if there's nothing to account for Thermal Expansion in a "closed plumbing system" it will effect everything connected to it such as the faucets, taps, Toilets, Dishwashers, Washers,etc.

From my estimation not installing a Thermal Expansion tank or other approved device in a closed plumbing system would be classified as in "improper installation". If we as a company are approving water heater replacements with no Thermal Expansion control in closed plumbing systems would a company be able to exercise "plausible deniability".

From my vantage point this is a systemic problem for our Company. Most of our plans have coverage for code violations, requirements or upgrades. We should be ensuring that Thermal Expansion tanks are installed since we cover for it, and the plumbing code mandates that it be done when it comes to replacing a Water Heater in a closed plumbing system. Now I have been advised I shouldn't pursue this when approving a Water Heater replacement. I was advised if a plumber doesn't mention that it's needed than I'm forbidden from asking if there's a closed plumbing system, and advising them to install a Thermal Expansion tank or other approved device to control thermal expansion if there is.

To me it seems completely soulless and unethical for our company to approve water heater replacements in closed water systems with no means of thermal expansion and by doing that we're compromising the homeowners entire plumbing system which is going to cost our Company on the back end once everything connected to it starts to fail. Wouldn't this practice be unlawful, to me plausible deniability shouldn't apply. This is the uniform standard.

Sorry for the winded post. But I've become completely deflated knowing that I'm complicit in compromising plumbing systems by approving improper installations all across the country. Our company doesn't hire the best technicians, they hire the cheapest ones, and from what I've seen some of them are about getting in and out as fast as they can with no regard to the plumbing codes. Some of our Plumbers always install the Tanks, but more don't than ones that do. Something isn't right here. Hopefully someone more informed can weigh in on this.

Thank you,

Edited 2 times.

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 Re: Thermal Expansion Tanks, UPC CODE 608.3
Author: hj (AZ)

When my heater had to be replaced, the warranty plumber wanted to install an expansion tank, among other things, and ADD that to my deductible amount, (about $235.00 extra), even though NONE of the things he wanted to do were necessary.

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 Re: Thermal Expansion Tanks, UPC CODE 608.3
Author: kormanicus (CA)

Most Warranty companies will allocate $250 per plan term for code upgrades. If you were to attain their premium plans many of them go as high as $1000. The base standard plans offer no allocation for code requirements. Hopefully you had the tank installed. If not you're compromising everything connected to your water system and the Manufacturers warranty will be voided on your Tank.

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 Re: Thermal Expansion Tanks, UPC CODE 608.3
Author: packy (MA)

under my code a water heater replacement requires a plumbing permit and a subsequent inspection. if the inspector approves the installation and leaves the required approval tag then the presence of an expansion tank is a moot point.
if the expansion tank leaks and someone removes it and plugs the pipe or installs a smaller tank that doesn't take up the expansion, how are you supposed to know?
if the water heater is replaced with no permit you would know as there would be no approval tag hanging. but if the tag fell off and is lost, how are you supposed to know?
too many scenarios here to come up with a 100% definite answer.

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 Re: Thermal Expansion Tanks, UPC CODE 608.3
Author: hj (AZ)

You obviously do NOT know how the "manufacturer's warranty" works. The plumber removes the heater, takes it to a dealer, they remove the i.d. tag, SCRAP the heater, and give you a replacement. NOBODY LOOKS AT THE INSTALLATION TO SEE IF THERE IS A PROBLEM WITH IT.

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 Re: Thermal Expansion Tanks, UPC CODE 608.3
Author: packy (MA)

i have never removed a heater, returned it to the supply house for them to remove the tag.
in fact i have never seen any other plumbers do this.
all they want is the tag.
the three supply houses i do business with carry, one has bradford white, one has americam and one has state.
no one has ever brought in a tank unless it is the first year of use in which case the manufacturer wants the tank back so they can see what went wrong.
in fact i order a replacement, have it delivered to the job site and give the truck driver the sticky tag from the old heater.

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 Re: Thermal Expansion Tanks, UPC CODE 608.3
Author: PlumberLoren (CA)

Just because you do not see a backflow device i.e. a check valve, doesn't indicate that there is none in your system. Many water meters have a check valve built in to them because the water provider does not want any water to come back through the meter into their system because they have no idea what you, the end user have done to that water. It is possible that you were using a hose end sprayer to apply pesticides in your back yard or garden. If that were the case and the Water System in the street were to have a large break, it could cause water in your system to syphon back into the City System , tainting the water and making in not potable. If your water heater pressure relief valve fails to respond to a high pressure your system would be very dangerous. It might be a good idea to install a pressure relief valve on the cold water system. This is one good reason to test your water pressure occasionally to make sure your water pressure is less than 80 psi, I always suggest around 60 PSI to my friends. The diaphragms inside the pressure reducing valves consists of a spring and rubber that wears out and splits over time. You might also call your water company and ask them if there is a check valve or backflow valve built into your meter? Do yourself a favor and purchase a pressure gauge and check your pressure at a garden hose outlet. You may save yourself a lot of money and a claim to your insurance company should one be warranted.

I will end this message by stating that heating water is no longer as simple as it once was. The new Water heaters have more sensors, pilot valve safety features and connections to the water nipples that isolate in an attempt to save the water heater from being destroyed by electrolysis and water minerals. Securing and Venting has also changed causing the installer to be more aware of the new Plumbing code. It just isn't simple any more.

Go to: [www.bradfordwhite.com]

for an example of a new installation of a condensing Water heater by Bradford White.

Edited 3 times.

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